Vietnam reported Monday more bird flu outbreaks among poultry, underscoring the difficulty in stopping the spread of the disease, which has killed 31 people in Asia this year.
Last week, some 3,000 chickens from three private farms in southern Tien Giang province died or were culled after they were suspected of contracting the disease, said Cao Van Hoa, deputy director of the provincial agriculture department.
Hoa said samples have been sent to the regional animal health center in Ho Chi Minh City for testing, and results were expected in a week.
In Soc Trang province, about 230 kilometers (140 miles) southwest of Ho Chi Minh City, authorities culled some 400 chickens at a farm after 500 birds died on Oct. 1, an official from the provincial animal health bureau said.
Meanwhile, authorities in the southern province of Long An have culled more than 2,300 chickens after about 250 birds from two farms died from the disease on Sept. 30, provincial officials have said.
The villages where the outbreaks were reported have been disinfected and the transportation of poultry to or from the affected districts has been banned, the officials said.
Bird flu has killed or forced the cull of more than 43 million poultry in Vietnam. It has also jumped to humans, killing 20 here and 11 in Thailand.